Color television



March 29, 1949. H.7E. LEGLER 2,465,652

COLOR TELEVISION Filed June 25, 1946 FIG.

FIG. 2.

ffcu y L @j/ZT Patented Mar. 29, 1949 UNITED STATES PATENT OFFICE COLORTELEVISION Harry E. Legler, Hiawatha, Kans.

Application June 25, 1946, Serial No. 679,113

1 Claim. 1

This invention relates to devices for color separation for televisiontransmission and reception.

An object of the invention is to provide a device and system for colorseparation for television transmission and reception which makes use ofoptical separation of colors.

Another object of the invention is to provide means for color separationfor television transmission and reception in which the original image isoptically formed into four differently colored images thrown onto thepick-up tube screen simultaneously for transmission by the usualtelevision apparatus and then are optically re-combined into the formand color of the original image.

A further object of the invention is to provide an optical colorseparation system for television transmission and reception which isimple in construction, relatively inexpensive to manufacture, andeffective in operation.

Other objects and advantages of the invention will become apparent fromthe following description of a preferred embodiment thereof, asillustrated in the accompanying drawings, and in which:

Figure 1 is a perspective view of the optical elements according to theinvention, shown in relation to a cathode ray tube for televisionpurposes.

Figure 2 is a face view of the color filter side of the larger prismshown in Figure 1, showing the color break-down.

This system of color television makes use of optically separated colorsinstead of, as in the prior art, mechanically separated colors such asare obtained by driving a drum or disc in the transmitting equipment insynchronism with a motor-driven disc or drum in the receiving equipment.Therefore, the problem of synchronism of color-separated images isentirely eliminated according to my invention.

To do this, I use a system for simultaneously producing four images 2,4, 6, and 8 on the mosaic IU of a television iconoscope or orthiconpick-up tube l2 from a single scene indicated generally at I4, each ofthe four images having been passed through one of four different colorfilters l6, I8, 26 and 22 on prism 24, thus separating the originalscene l4 into its basic colors for transmission of the scene by suitabletelevision apparatus connected to the tube :2, and not shown in thedrawings.

The four separate images 2, 4, 6, and 8 are scanned by the pick-up tube[2 as one frame and transmitted in any usual manner well known in theart over any television equipment and circuits without requiring anyfurther electrical or mechanical change in the transmitting equipment.

This is accomplished by passing the subject image i i through a suitablefocusing lens 26, thence into a fi st light-dividing prism 28 whichconsists of a partial. reflecting mirror surface 30 and a totalreflecting surface 32. The partial reflecting surface 36 divides thelight represented generally by ray 34 equally, one-half passing throughthe prism alon the path indicated by line 36 and continuing into thesecond light-divioling prism 2G. The other half of the light from my 34is reflected at right angles to its original path to total reflector 32,where it is again reflected 90, bringing it into parallelism with itsoriginal path and along the path. indicated by ray 38 into prism 2 1.

In prism 24, the two beams 36 and 38 are each divided again equally bypartial reflecting surface 4%, one-half of each of the two beams 36 and38 continuing on through the surface 66, and two of the color filters 2eand 22 to the mosaic It on tube E2 to register images at 6 and 8. Theother two halves are reflected at right angles upward along pathsindicated by 3-32 and M to total reflecting surface 46, where they areagain reflected at right angles along paths 4B and 5!] parallel to theiroriginal directions, and through filters l6 and 13 to register images 2and 4 on the tube mosaic it. The four colors used in filters l6, I8, 26and 22 are such that when superimposed or added together will producewhite light. Ordinarily, there is no spacing between prisms 28 and 25and between prism 24 and mosaic ill on tube $2, the spacing being shownonly for clarity of illustration.

In the receiving and reproducing equipment, the cathode rayreceivingtube will register the four images on the screen of the tube as oneframe. Each image will be viewed or projected through its proper colorfilter, the image then passing back through the same kind of opticalsystem as is illustrated for the transmitting station, the imagescombining into one composite scene and being viewed or seen in thenatural color of the original scene.

Although I have described a preferred embodiment of my invention inspecific terms, it is to be understood that various changes may be madein size, shape, materials and arrangement without departing from thespirit and scope of the invention as claimed.

I claim: from each of said four images all but one prede- Colortelevision transmitting apparatus comtermined color. prising a,television pick-up tube having a mosaic HARRY E. LEGLER. screen, a lensspaced from said screen for focusing an image of a scene to betelevised, a first 5 REFERENCES CITED prism for forming said images intotwo identical The following references are of record in the side-by-sideimages disposed between said lens file of this patent:

J [and said screen and ad acent said lens, a second prism disposedbetween said first prism and said UNITED STATES PATENTS screen forreceiving light from said first prism 10 Number Name Date and formingsaid two side-by-side images into 2,335,130 Goldsmith 23 1943 two pairsof identical side-by-side images of the 2,389,645 Sleeper 27, 1945 samescene, and filter means interposed between 2,339,646 sleeper 27, 1945said second prism and said screen for filtering

